I'm sure there's a definitive answer to that question floating around somewhere. I can only offer my own limited understanding.

Basically, an internal style makes use of body mechanics in a slightly different way.
The specifics vary depending on the style, but generally it's about cultivating sensitivity, awareness, balance, and natural movement to divert, deflect, and reroute inertia to the other guy's disadvantage. Each of the arts has a different flavor, and each style within each of the arts has it's own emphasis.

It's more about physics than muscular strength.

Sometimes, yes, there is internal bleeding, but that's got nothing to do with the name. :)

"Internal styles" subject is quite large and not really fit for newbietown. There are plenty of people here who practice internal arts, including myself. But I'm more likely to let my yang overbear my yin, if you know what I mean.

“We are surrounded by warships and don’t have time to talk. Please pray for us.” — One Somali Pirate.

"Internal styles" subject is quite large and not really fit for newbietown. There are plenty of people here who practice internal arts, including myself. But I'm more likely to let my yang overbear my yin, if you know what I mean.

If you're really a mantis guy, I know EXACTLY what you mean. :)

I've been known to get a little too yang myself at times, but then, that's why I work on it, right.